Electric transmission of graphic representation



Feb. 14, 1928. 1,659,200

- 0. F. JENKINS ELECTRIC TRANSMISSION OF GRAPHIC REPRESENTATION Filed April 22. 1926 Charies Francis Jenkins Patented Feb. 14, 1928.

UNITED STATES CHARLES FRANCIS JENK INS, WASHINGTON, DISTRICT 0! 001ml.

ELECTRIC TRANSMISSION OF GRAPHIC REPRESENTATION.

Application filed April 22, 1926. Serial No. 103,898.

This invention relates to electric transmission of graphic representations, such as pictures, printed matter, writing or the l ke so that any desired graphic representation may be transmitted and duplicated at any desired point. The transmission may be accomplished by electrical currents of the nature transmitted over conductors or the ether, as by the use of radio frequency oscillations.

The invention further relates to the transmission of graphic representations, whether composed of visual variations in intensity upon a base material in single color wor or multi-color efiects, which, by waymf ex- I vam 1e, may include meteorological maps, m ti-colored prints, printing 'or the like, 'news matter reproduced from the newsprint material, etc.

The invention has for an object thereof the provision of aprocess whereby a graphic representation may be transmitted by converting the variations in representative effects into an electrical currentwhich may 26 subsequently be reconverted to again record a duplication of the original graphic representation.

The invention contemplatesenergizing a light sensitive cell in accordance with variaan tions in intensity of a graphic representation upon its base material to transmit an electrical current capable of -reproducing,through appropriate receiving apparatus, substantial 'equivalents of the graphic representation used for energizing the light sensitive cell.

A further object of my invention resides in the provision of a method for transmitting electrical current varying in intensity and controlled by a graphic representation 40 so that upon subsequent reconversion of the electrical current a representation may be obtained simulating in character the original graphic representation.

The invention contemplates the energizing of a light sensitive cell to generate an electrical control of a transmltting circuit in accordance with the varitions in intensity of a graphic representation upon its base material.

My invention still further contemplates the provision of a method for energizmg a light sensitive cell which includes correlating the energization of the light sensitive cell to the intensity of a graphic representation upon its base, whereby a current is transmitted in strength not greater than the relative intensit of the re resentation upon its base materia and where y, when the current is reconverted into a record, substantial equivalent of the original graphic representation transmitted is obtained avoidin blurring or other distortion .of the origina graphic representation and with greater fidelity of reproduction than with any other means known to me.

The invention still further contemplates the provision of means for the energization of a light sensitive cell in accordance with the sensitivity of the cell to transmit a current in proportions not relatively greater than the intensity of a graphic representation which it is desired to transmit upon its base material and one wherein the effect produced in the reconversion of the elec- The invention, in its more particular embodiment, has for anobject thereof the provision of .a method of aphic transmission which includes pulsatmg light upon a graphic representation and energizing a light sensitive cell in accordance with the variations in intensity of the graphic representation upon its base material by transmitting fractional areas of the graphic representation progressively until predetermined areas of said representation have been traversedby the pulsating li ht, whereby a current is transmitted capabi of being reconverted into a record simulating in character the original representation.

In a preferred embodiment of my invention, a transmission'device is provided which includes means for projecting fractions of predetermined areas of a graphic representation by energizing a light sensitive cell in amounts substantially equivalent to said fractional areas, the graphic representation and the light sensitive cell being so positioned relative to each other to avoid energizing of the light sensitive cell in amounts varying substantially beyond the limits in which the graphic representation varies upon its base material.

In the attainment of the foregoing objects, togetherwith such further objects and additional benefits and advantages as ma herematter appear or be pointed out, A have provided a construction, one embodiment of which is illustrated in the accompanying drawings, wherein- Figure 1 is a plan view of a duplex transmitting and receivin device;

Figure 2 is a detail taken on aline A-B of Figure 1;

Fi re 3 is a section taken on the line CI of Figure l; and

Figure 4 is an enlarged detail of a portion of Figure 2.

For the practice of my invention there is provided a light sensitive cell which may be a photochemical cell, selenium cell, potassium cell or a similar light rece tion. evice which is ca able of converting ght energy to small e ectrical currents or where the energy of light may control an electrical circuit. There is further rovided a light source for energizing the ight sensitive cell previously mentioned which 1i ht source is arranged to energize a light ce in accordance with a grap ic representation which is sought to be transmitted. Preferably the light source is of such nature for the transmission of any graphic representation so that independently of combination with other means of control it will not var the energization of the light upon the lig t sensitive cell but will function in accordance with the variations in intensity of a graphic representation upon its base material. Control of the li ht upon the light sensitive cell through t e medium of the graphic representatlon may be accomplished either by transmitting the light directly through the graphic representation as, for instance, when the raphic representation is mounted upon a 1i m transparent or translucent surface, such as a photographic film or the like, or by reflection from the surface of the base material upon which the graphic representation is mounted. Fractional areas of the graphic representation are submitted to the activity ofthe light medium so that the light sensitive cell is energized accordingly. Thefractional areas are presented progressively un til predetermined areas of the graphic re resentat-ion have been traversed and the hght sensitive cell has been energized in accordance with the variations in intensity thereof.

The light sensitive cell and the light energy are preferably so positioned relative to each other and to the graphic representation which it is desired to transmit so that when fractional areas of the graphic representation are used to control the energization of the light sensitive cell, the energization will not be greater than the variation in intensity of that fractional area of the base material upon which the graphic representation is mounted and to ot er portions thereof. Thus I referably correlate the energization of the hght sensitive cell to the intensity of the graphic representation upon its aae whereb the current is transmitted in stren t not greater than such intensity and thereEy a blurring or distortion of the transmitted image is avoided. Preferabl I corielate the energization of the light cc to the intensity of the graphic representation upon its base by pulsating light or interru ting the same in accordance with the sensitivity of the cell to transmit a current in proportions not relatively greater than the variations in intensity of the graphic representation upon its base material.

More particularly and preferably, the fractional areas of the graphic representation are so small and positioned in such proximity to the light sensitive cell that when I use a light source of a size greater than the predetermined fractional area,-the light sensitive cell is not energized to an extent greater than the degree of intensity of the fractional area to other portions of the graphic representations;

For the practice of the method'of transmission of graphic representations, there is preferably provided means for mounting an object to be transmitted so as to progressively present predetermined fractional areas thereof to the illumination of a source of light which is caused to be projected on the graphic representation and therefrom energize a light sensitive cell arranged to move relatively to the graphic representation until predetermined areas have been traversed.

In the illustration shown in Figure 1, 1 is a source of power, as a motor, arranged to drive the hollow shaft 2 by means of a worm gear 3. Upon this shaft there is mounted a hub member 4, arranged to hold a drum member 5 preferably made of a transparent material such as glass or the like. To this drum there is attached, either on its outer side or within its walls at the periphery thereof, a graphic representation desired to be transmitted and herein designated as TS. Mounted to rotate concentrically with the drum 5 upon a shaft 6 there is provided a light pulsating or interrupting member 7 in the form of a cage 8 having suitably spaced longitudinal members 9. Preferably the shaft 6 is rotated at a speed of revolution which is high relatively to that of the drum 5 by the motor 1 by means of the pulleys 1" and a belt 11.

It will be observed that the speed of 1'!)- tation of the cage and the relation of the spaced longitudinal members 9 will determine the degree of pulsations or interruptions of the energizing of the light sensitive cell and the greater the interruptions and pulsations, the finer will be the analysis of the graphic representation within limits of sensitivity of t e light cell.

It 'will be observed that while the cage 8 is iven a higher s eed of revolution than the mu 5, for furt er increasing the relative speed of movement these members may be rotated in opposite directions. Concentrically arranged within the drum 5 and the cage 8 I provide a source of illumination here shown in the form of an incandescent lamp 12. This is preferably of a form having the filament 13 thereof of extended length and generally equivalept to the size of the graphic representation attached to the drum 5.

For translating the li ht ener into electrical currents in acco ance wit the variations in intensity of the graphic representation upon its base material, there is provided a light sensitive cell 14 tangentially arranged in repect to the drum 5 andin close proximity thereto so as to just clear the peripheral surface. The light sensitive cell'is preferably housed within a shell 15 provided with a small aperture 16 which is directed towards the filament 13 previously described. Thus in the rotation of the drum'5 in reference to the light sensitive cell, small areas of the graphic representation will be presented in front of the aperture 16 and between the light source 13 so as to energize it in accord ance with the intensity of the area of the graphic representation upon its base material.

To present the predetermined areas of the graphic representation progressively to the light sensitive cell, the latter is moved along the length of the drum during the rotation of the drum 5 and for this purpose I provide a longitudinal screw threaded member 17 parallel to the axis of the drum and which is caused to be rotated by the train of gears 18. and 19 at a relatively slow speed of revolution. The threaded clutch member 20 is provided for the light sensitive cell so as to engage with the screw threaded member 17 in the position shown and, by engagement therewith during the rotation of the latter, will be caused to traverse the length of the drum. Thus during the rotation of the drum 5 and the movement of the light sensitive cell, every portion of the graphic representation TS will be interposed between the light source 13 and the aperture 16, encrgizing the light sensitive cell circuit in accordance with the variations in intensity of the graphic representation upon its base material.

It will thus be observed that as the small a rcns of the member TS are presented before the light sensitive cell, the latter will be energizcd by the, light assing through the member TS in accor ance with the variations in intensity of the graphich representations. In order, however, to energize this cell in accordance with its sensitivity and propertes to transmit a current in proportions to light fractions not relatively greater than the fractional areas under consideration bear to the entire graphic representation subjected to light, the source of light is caused to be pulsated or interrupted. Thus any lag in current transmission due to encrgization of the light sensitive cell by the light source 13 will be controlled and at the receiving end of the circuit there will he a substantially true representation in accord ance with the variations in intensity of the graphic representation upon its base material.

It will also be observed that by arranging the light sensitive cell tangential to and in close proximity to the graphic re resentation, only so much of the light sensitive cell will be energized as is represented by that portion in front of the aperture 16. Thus the pulsations of current mounted from and controlled by the light sensitive cell will be in accordance with the variations in intensity of the graphic representation.

In Figure 4 there is shown enlarged details of the receiving end of in device in which the drum 5' has mounte thereon'a light reactive film. Tan entially arranged to the drum'5 I arrange t e lamp 14' within the shell 15'. An aperture 16' is provided so as to be in close proximity with the drum 5.

The filament of the lamp 14' indicated at 21 is arranged to be actuated by the current generated by a transmitting device and the glow point 22 is positioned preferably so as to be in close proximity with the aperture 16. Thus it will be observed that as the current generated by the transmitter pulsates or is interrupted, the glow portion 22 will be caused to fluctuate in substantially equal intensity and direct a beam of light upon the recording surface of the drum 5' in accordance with the fluctuations of current within the circuit.

In the illustration shown in Figure 1 the left hand portion of the device is arranged to receive transmitted pulsations of current and the fluctuating light member 14' is arranged to produce a record upon a light reactive member, such as a photographic film, which is mounted on the drum 5. The rotation of the drum 5 and the feed of the lamp 15 are synchronized with the rotation and feed of the transmitting drum and light sensitive cell.

It will thus be observed that I am enabled to obtain a record produced by a fluctuating current which varies in intensity in accordance with a graphic representation transmitted and that by synchronizing the rotation ofthe drum 5/aud the lamp 14: there is obtained a reproduction of the graphic representation.

It will also be noted that the cage 8 may be opaque or of varied translucency and, particularly for multiple colored work, may be arranged to act as a color screen so that by repetition of transmission the apparatus may be arranged for van-colored transmission.

Having thus described my invention and light sensitive cell for receiving the light illustrated its use, what I claim as new and passing through the transparency, and a rol0 desire to secure by Letters Patent, is-- tating cage-like member between said trans- In a graphic transmission device, the comparency and said light source.

5 binution of a figured transparency, a 1'0- In testimony whereof I have hereunto tating cylinder for sup orting said transsigned my name, parency, a light source or illuminating the transparency from inside the cylinder, :1 CHARLES FRANCIS JENKINS. 

